Thyroid disease in women

Types of Thyroid Disease in Women

Women are far more likely to have problems with the thyroid than men. Studies have shown that one in eight women tend to develop thyroid disease during her lifetime. Sometimes, menopause symptoms can be mistaken for thyroid problems, but thyroid disease is more likely to develop after menopause.

We have already established the definition and the effects of hypothyroidism and hyperthyroidism in previous articles.
Let’s briefly describe the above conditions: Thyroiditis is the inflammation of the thyroid gland. This inflammation may be caused by several factors that includes autoimmune diseases, infection and certain medications. Postpartum thyroiditis is a type of thyroiditis that develops during pregnancy or after childbirth. It is thought to occur from an underlying autoimmune condition that gets triggered during pregnancy. Thyroid nodules are the abnormal growth of cells that forms into a lump in the thyroid gland. Generally this lump is non-cancerous or benign. Sometimes however, nodules can be malignant and thus become a sign of thyroid cancer. Goiter, on the other hand, is general enlargement of the thyroid gland. It can be associated with either hypothyroidism or hyperthyroidism.

Thyroid Hormone Imbalance and Reproductive Health

When the thyroid gland is enlarged, it affects the production of the thyroid hormone in the body. The levels can either become too high (hyperthyroidism) or too low (hypothyroidism). As already discussed, imbalance of the thyroid hormone level affects major bodily functions that can disturb both your physical and mental health.
Since the thyroid hormone is very important for a number of metabolic processes, a malfunctioning thyroid can cause several potentially dangerous problems specifically in women. These problems include:

Menstrual Problems
An unbalanced thyroid hormone production can result in light, heavy, painful or irregular periods. It can also make your period stop for more than several months. This is a condition called amenorrhea.

Problems Getting Pregnant
Thyroid disorders can cause many reproductive problems in women. Scientific studies have established link between hypothyroidism or hyperthyroidism, and infertility. These thyroid diseases can affect the ovulatory cycle of women.
The two main hormones that affect ovulation are LH (luteinizing hormone) and FSH (follicle stimulating hormone). However, when either hypothyroidism or hyperthyroidism is present in the body, the misbalanced thyroid hormone level can alter the balance of FSH and LH.
Hypothyroidism may also cause your body to produce more prolactin. Prolactin is another hormone that tells your body to make milk. Too much prolactin can also prevent ovulation.

Problems during Pregnancy
Two pregnancy-related hormones cause increased thyroid levels in the body. These hormones are hCG (human chorionic gonadotropin) and estrogen. hCG is made by the placenta and acts very similar to the function of the hormone TSH (thyroid-stimulating hormone).
TSH, made by the pituitary gland in the brain, is the hormone responsible for stimulating the thyroid gland to produce the thyroid hormone. Increased TSH therefore stimulates extra thyroid production.

Similarly, the presence of increased estrogen in the body (due to pregnancy), produces higher levels of a certain protein that transports the thyroid hormone into the blood. This protein is better known as thyroxin-binding globulin, or thyroid-binding globulin due to its binding capacity.

Although these hormone changes are completely normal, they can sometimes make it difficult to interpret thyroid function tests during pregnancy. These tests are important for the pregnant women because the level of thyroid hormone in the mother’s body affects the growth of the fetus.

Regular thyroid hormone production is vital for the normal development of the fetal brain and nervous system. During the first trimester, the mother’s thyroid hormone acts as the unborn baby’s source of thyroid hormone. This happens because the baby’s thyroid gland doesn’t begin to function on its own, until the fetus is 12 weeks old.

It is normal for thyroid levels to elevate slightly and for the thyroid gland to slightly enlarge during a healthy pregnancy. However, when the thyroid is significantly enlarged, this can be a sign of thyroid disease and it is essential to be evaluated. Due to higher levels of thyroid hormone in the blood, along with increased thyroid size, fatigue, and many other symptoms typical of pregnancy, thyroid problems can be difficult to diagnose during pregnancy.

Medical Insight

Being aware of the above conditions helps to avoid possible complications. The presence of certain predisposing factors like family history or past medical history of thyroid disease, should make you more vigilant to look out for the mentioned symptoms. It is never too late to take care of yourself. Seek the help of your health care provider so that you may understand what has gone wrong, what needs to be avoided and what you can do to correct the situation.

References:

National Institute of Diabetes and Digestive and Kidney Diseases, U.S. Department of Health and Human Services http://www.niddk.nih.gov/health-information/healthtopics/endocrine/pregnancy-and-thyroid-disease/Pages/fact-sheet.aspx

U.S. National Library of Medicine http://www.nlm.nih.gov/medlineplus/thyroiddiseases.html#cat7
Office on Women’s Health, U.S. Department of Health and Human Services http://womenshealth.gov/publications/our-publications/fact-sheet/thyroid-disease.html